The present invention relates to an apparatus for and method of image recording and reading, an apparatus for and method of image recording, and an apparatus for and method of image reading, such as a facsimile apparatus.
It is well known that a facsimile apparatus has a function of image recording to record an image in accordance with image data received from another apparatus through a transmission line, a function of image reading to read an image recorded from an original in order to transmit image data to another apparatus, a function of network controlling to receive and transmit information through a transmission line, and a function of modulation and demodulation to modulate information into image data and demodulate image data into information. The image recording is usually carried out by a recording head on recording paper transferred directly by a motor or indirectly through a transmission mechanism. Also, the image reading is carried out by a reading sensor to read an image while the original is being transferred using a motor.
Conventionally, the image recording by an apparatus of this type is controlled by matching the output timing of a driving signal for a motor for the transfer of a recording paper with that of a driving signal for recording which is supplied to a recording head in accordance with the image data. However, in the case of such a controlling operation, a problem that recording is started at a position ahead of the proper position where the recording should actually be made arises because of influences caused by delays in starting the motor and in the transmission system and elsewhere in the apparatus. Particularly, in the case of a solid recording, a striped pattern having dark and light lines is recorded in the direction of the main scanning (the transverse direction transverse to the direction of movement of a recording paper), and in some cases, white striped lines (linear blanks) appear. This kind of problem also occurs in image reading. In other words, when an image recorded on an original is read, a different image from the actual one is read because of influences caused by delays on starting a motor for the transfer of the original and in the transmission system and elsewhere in the apparatus.
In connection with the above-mentioned problem, it has been known to prevent the occurrence of blanks in facsimile apparatus, particularly, one using a method of thermal image recording. In Japanese Laid-Open Patent No. 39272/1988, a technique to record the same data twice at the same position at the time of receiving the data is disclosed as a method to prevent the above-mentioned blank spaces.
This disclosed technique to prevent the above-mentioned blank spaces utilizes the expansion of the area of each dot resulting from the recording of the same data twice by the thermosensitive head at the same position. Therefore, a difference between the position at which a recording should be made and the position at which it is actually made still exists because of delays in starting the motor and others, and a striped pattern of dark and light lines tends to occur when a solid recording or the like is carried out. Furthermore, since the same recording is repeated, the required time for recording becomes twice as long, which still presents a problem to be solved for the achievement of high speed recording.
In the Japanese Laid-Open Patent mentioned above, no disclosure is made at all as to the resolution of drawbacks existing in the image reading.